Enhancer looping protein LDB1 affects T-ALL cell proliferation by cooperating with master transcription factors [CUT&Tag]

LIM domain-binding protein 1 (LDB1) is a highly conserved and widely expressed chromatin looping protein that connects enhancer-promoter genes through LIM and LIM homologous domains in various cell types. LDB1 has been confirmed to play a crucial role in various physiological and pathological processes. In our study, we aim to investigate the function and mechanisms of LDB1 in the context of T-cell acute lymphoblastic leukemia (T-ALL). RNA-seq was conducted and the differently expressed genes were revealed in the LDB1-knockdown 6T-CEM and J.gamma1 cells in comparison to control group. Cleavage Under Targets and Tagmentation (CUT&Tag) showed the co-localization of LDB1 with several master transcription factors on chromatin in 6T-CEM cells. CUT&Tag using antibody against LDB1, ERG, ETV6, IRF1, H3K27ac in 6T-CEM cells, antibody against LDB1 in MOLT4 and Loucy cells.

LIM结构域结合蛋白1（LIM domain-binding protein 1, LDB1）是一类高度保守且广泛表达的染色质环化蛋白，可在多种细胞类型中通过LIM结构域与LIM同源结构域介导增强子-启动子基因的连接。现已证实，LDB1在多种生理及病理过程中发挥关键调控作用。本研究旨在探究LDB1在T细胞急性淋巴细胞白血病（T-cell acute lymphoblastic leukemia, T-ALL）中的功能与作用机制。研究中我们开展了RNA测序（RNA-seq），对比对照组与LDB1敲低的6T-CEM及J.gamma1细胞，筛选得到差异表达基因。靶向切割与标签化（Cleavage Under Targets and Tagmentation, CUT&Tag）实验显示，在6T-CEM细胞中，LDB1与多种核心转录因子在染色质上存在共定位。此外，本研究在6T-CEM细胞中使用针对LDB1、ERG、ETV6、IRF1及H3K27ac的抗体开展CUT&Tag实验，同时在MOLT4与Loucy细胞中使用针对LDB1的抗体完成该实验。